occ.rst (4779B)
1Kernel driver occ-hwmon 2======================= 3 4Supported chips: 5 6 * POWER8 7 * POWER9 8 9Author: Eddie James <eajames@linux.ibm.com> 10 11Description 12----------- 13 14This driver supports hardware monitoring for the On-Chip Controller (OCC) 15embedded on POWER processors. The OCC is a device that collects and aggregates 16sensor data from the processor and the system. The OCC can provide the raw 17sensor data as well as perform thermal and power management on the system. 18 19The P8 version of this driver is a client driver of I2C. It may be probed 20manually if an "ibm,p8-occ-hwmon" compatible device is found under the 21appropriate I2C bus node in the device-tree. 22 23The P9 version of this driver is a client driver of the FSI-based OCC driver. 24It will be probed automatically by the FSI-based OCC driver. 25 26Sysfs entries 27------------- 28 29The following attributes are supported. All attributes are read-only unless 30specified. 31 32The OCC sensor ID is an integer that represents the unique identifier of the 33sensor with respect to the OCC. For example, a temperature sensor for the third 34DIMM slot in the system may have a sensor ID of 7. This mapping is unavailable 35to the device driver, which must therefore export the sensor ID as-is. 36 37Some entries are only present with certain OCC sensor versions or only on 38certain OCCs in the system. The version number is not exported to the user 39but can be inferred. 40 41temp[1-n]_label 42 OCC sensor ID. 43 44[with temperature sensor version 1] 45 46 temp[1-n]_input 47 Measured temperature of the component in millidegrees 48 Celsius. 49 50[with temperature sensor version >= 2] 51 52 temp[1-n]_type 53 The FRU (Field Replaceable Unit) type 54 (represented by an integer) for the component 55 that this sensor measures. 56 temp[1-n]_fault 57 Temperature sensor fault boolean; 1 to indicate 58 that a fault is present or 0 to indicate that 59 no fault is present. 60 61 [with type == 3 (FRU type is VRM)] 62 63 temp[1-n]_alarm 64 VRM temperature alarm boolean; 1 to indicate 65 alarm, 0 to indicate no alarm 66 67 [else] 68 69 temp[1-n]_input 70 Measured temperature of the component in 71 millidegrees Celsius. 72 73freq[1-n]_label 74 OCC sensor ID. 75freq[1-n]_input 76 Measured frequency of the component in MHz. 77power[1-n]_input 78 Latest measured power reading of the component in 79 microwatts. 80power[1-n]_average 81 Average power of the component in microwatts. 82power[1-n]_average_interval 83 The amount of time over which the power average 84 was taken in microseconds. 85 86[with power sensor version < 2] 87 88 power[1-n]_label 89 OCC sensor ID. 90 91[with power sensor version >= 2] 92 93 power[1-n]_label 94 OCC sensor ID + function ID + channel in the form 95 of a string, delimited by underscores, i.e. "0_15_1". 96 Both the function ID and channel are integers that 97 further identify the power sensor. 98 99[with power sensor version 0xa0] 100 101 power[1-n]_label 102 OCC sensor ID + sensor type in the form of a string, 103 delimited by an underscore, i.e. "0_system". Sensor 104 type will be one of "system", "proc", "vdd" or "vdn". 105 For this sensor version, OCC sensor ID will be the same 106 for all power sensors. 107 108[present only on "master" OCC; represents the whole system power; only one of 109this type of power sensor will be present] 110 111 power[1-n]_label 112 "system" 113 power[1-n]_input 114 Latest system output power in microwatts. 115 power[1-n]_cap 116 Current system power cap in microwatts. 117 power[1-n]_cap_not_redundant 118 System power cap in microwatts when 119 there is not redundant power. 120 power[1-n]_cap_max 121 Maximum power cap that the OCC can enforce in 122 microwatts. 123 power[1-n]_cap_min Minimum power cap that the OCC can enforce in 124 microwatts. 125 power[1-n]_cap_user The power cap set by the user, in microwatts. 126 This attribute will return 0 if no user power 127 cap has been set. This attribute is read-write, 128 but writing any precision below watts will be 129 ignored, i.e. requesting a power cap of 130 500900000 microwatts will result in a power cap 131 request of 500 watts. 132 133 [with caps sensor version > 1] 134 135 power[1-n]_cap_user_source 136 Indicates how the user power cap was 137 set. This is an integer that maps to 138 system or firmware components that can 139 set the user power cap. 140 141The following "extn" sensors are exported as a way for the OCC to provide data 142that doesn't fit anywhere else. The meaning of these sensors is entirely 143dependent on their data, and cannot be statically defined. 144 145extn[1-n]_label 146 ASCII ID or OCC sensor ID. 147extn[1-n]_flags 148 This is one byte hexadecimal value. Bit 7 indicates the 149 type of the label attribute; 1 for sensor ID, 0 for 150 ASCII ID. Other bits are reserved. 151extn[1-n]_input 152 6 bytes of hexadecimal data, with a meaning defined by 153 the sensor ID.